env：

1. Neo4j-4.4.x
2. neo4j-jdbc-driver 4.0.9
   想象一下，我执行下面的密码得到一个“教师”节点和一个“学生”节点，它们之间的关系是“教育”，并且关系有一个年份属性。
   密码：

merge (subject:Teacher{teacher_id: 'teacher_001'})  
merge (object:Student{student_id:'student_001'})  
merge (subject)-[relation:educate]->(object) set relation.year='3'  return subject,relation,object

图-1：

为什么我下面的方法在参数Map的帮助下不起作用？

@Test
public void testDeleteEdgeWithProperties_001() {
    Driver driver = GraphDatabase.driver("neo4j://localhost:7687", AuthTokens.basic("neo4j", "neo4j123"));
    Session session = driver.session();
    Transaction transaction = session.beginTransaction();

    String relationModelType = "educate";
    String subjectModelType = "Teacher";
    String subjectKey = "teacher_id";
    String subjectId = "teacher_001";
    String objectModelType = "Student";
    String objectKey ="student_id";
    String objectId = "student_001";

    Map<String, Object> properties = new HashMap<>();
    properties.put("year","3");
    Map<String, Object> params = new HashMap<>();
    params.put("relation_prop", properties == null ? new HashMap<>() : properties);

    // 删除
    String conditionDeleteCypher = " WHERE relation = $relation_prop";
    String cypher =  " MATCH (subject:" + subjectModelType + "{" + subjectKey + ": '" + subjectId + "'}) " +
            " MATCH (object:" + objectModelType + "{" + objectKey + ":'" + objectId + "'}) " +
            " MATCH (subject)-[relation:" + relationModelType +"]->(object) " +
            conditionDeleteCypher +
            " DELETE relation";

    System.out.println(cypher);
    transaction.run(cypher, params);
    transaction.commit();
    transaction.close();
}

通过上述方法打印的密码如下：

MATCH (subject:Teacher{teacher_id: 'teacher_001'})  MATCH (object:Student{student_id:'student_001'})  MATCH (subject)-[relation:educate]->(object)  WHERE relation = $relation_prop DELETE relation

然而，上面的密码可以在neo4j浏览器中成功执行（见下图2）。我这是怎么了感谢任何有用的回复
图2：

我尝试了几种方法来设置参数，但都不起作用。

String conditionDeleteCypher = " WHERE relation = $relation_prop";

String conditionDeleteCypher = " WHERE relation =+ $relation_prop";

String conditionDeleteCypher = " WHERE relation += $relation_prop";

我提供的@Test代码是完全可执行的，没有错误消息。执行后，neo4j浏览器仍然可以找到目标关系，说明该方法已执行但未生效。